Pilot-valve for hydraulic elevators.



No. 786,652. PATENTED APR. 4, 1905.

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-Bressum /O I TOT'L fi asses: 7 I 72 No.786,652. PATBNTED APR.4,1.905. 1r. LARSSON.

PILOT VALVE POE HYDRAULIC ELEVATORS:

APPLICATION FILED MAR.13,1902. RENEWED JAN. 12. 1905.

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UNITED STATES Patented April 4, 1905.

PATENT Ounce.

THURE LARSSON, OF l/VORCESTER, MASSACHUSETTS, ASSIGNOR TO STAND- ARD PLUNGER ELEVATOR COMPANY, A Y CORPORATION OF NEW JERSEY.

PILOT-VALVE FOR H YDRAULlC ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 786,652, dated April 4, 1905. Application filed March 13,1902. Renewed January 12, 1905. Serial No. 240,739.

To all whmn it may concern:

Be it known that I, THURE LARSSON, a subject of the King of Sweden and Norway, residing at Worcester, in the county of VVorcester and State of Massachusetts, have invented a new and useful Pilot-Valve for Hydraulic Elevators, of which the following is a specification.

This invention relates to that class of hydraulic valves which are employed for controlling elevators or for similar purposes in which the position of the main valve is controlled by a smaller supplemental valve or pilot-valve.

The especial object of this invention is to provide a strong, simple, and eflicient hydraulic-elevator valve of the class referred to which will occupy little room and which may be readily controlled from an elevator-car, to provide a novel connection between the main valve and the pilot-valve for closing the pilot-valve when the main valve has been moved to the desired position, and to house the parts, so that the same will be fully protected and not liable to bederanged.

- To these'ends this invention consists of the hydraulic-elevator valve and of the combinations of parts therein, as hereinafter described, and more particularly pointed out in the claims at the end of this specification.

In the accompanying two sheets of drawings, Figure 1 is asectional view of a hydraulie-elevator valve embodying my invention. Fig. 2 is a detail view, partly in section, illusmating the connection between the main valve and one of the screw-threaded sections which operate the pilot-valve, and Fig. 3 is a sectional view illustrating a slightly-modified form of construction.

To control the action of hydraulic elevators, comparatively large heavy valves are necessarily employed, and when direct-acting connections are used for shifting one of these valves from the elevator-car the elevator can be controlled only by exerting a considerable amount of power. To overcome this objection, compound hydraulic valves are now employed, in which the main valve is controlled by a smaller supplemental valve, termed the pilot-valve, which admits pressure to shift the main valve. In this class of constructions an arrangement of links or levers has hereto-- fore usually been employed to close the pilotvalve when the main valve has been moved to the desired position. In these constructions the pilot-valves may be made comparatively small and easily moved, so that the connections from the elevator-car to the pilot-valve can be readily operated and the elevator controlled with comparative ease. The specific object of my present invention is to provide a compact and efficient form of hydraulic-elevator valve which is adapted for use in substantially all locations and which comprises comparatively small number of working parts, and I accomplish this object by providing a screw-threaded connection between the main valve and the pilot-valve-that is to say, in the preferred form of hydraulic-ele vator valve embodying my invention the pilot-valve is arranged to be operated by a rod or connection having two sections adjustably threaded to each other. One section is connected to be actuated from the elevatorcar, while the other section is geared or connected to be turned from the main valve. The part of the screw-jointed connection which is shifted from the elevator-car may have a sliding or longitudinal movement, or, if preferred, the connections from the elevator-car may be arranged to turn or rotate the same.

Referring to the accompanying drawings for a detail description of a hydraulic-elevator valve constructed according to my invention, as shown in Fig. 1, A designates the easing of a main valve. The main-valve casing A is provided near its upper end with an exhaust-chamber 10, which may be connected by a passage 11 to a waste-pipe or other suitable outlet. The main-valve casing A is provided below the exhaust-chamber with a central chamber 12, which may be connected by a passage 13 to a hydraulic elevator. Below the central chamber 12 the valve casingA is provided with a pressure-chamber 1 1, which may be connected, through a passage 15, to any suitable source of hydraulic pressure,

lilounted in the valve-casing A is a. lining or pipe 16, which is provided with slots or openings near its middle for permitting connection between the central chamber 12 and the pressure-chamber 14 or exhaust-chz'imber 10, according to the position of the mainvalve pistons. The upper part of the valvecasing A may have a lining 17 litted therein, and the lower part of the valve-easingAnniy have a lining 18'litting therein.

Mounted in the valve-casing A is a mainvalve stem 19. The main-valve stem 19 is provided with two controlling pistons 21, which form the main valve. W hen the controlling-pistons 21 are in their central position, as shown in Fig. 1, the compartment 12 is shut off both from the exhaust-chamber and the pressuro-chamber14:. hen the controlling-mstons 21 are moved up, a passage is opened between the pressure-chamber 14-. and the central compartment 12, and when the controllinganistons 21 are moved down a pas-- sage is opened between the central compartment 12 and the exhmist-chamber1 0. At its lower end the nrainwalvc stem 19 is provided with an operatilig piston 2 2.

The parts as thus tar described may be snb-- stantially ol the same construction as employed in the ordinary main valves, for controlling hydraulic elevators.

Secured on the lower end of the siiipplemental casing A is a casing 23, and bolted onto the casing 23 a valve-casing 2a, in which the supplemental valve or pilot-valve is mounted, the axis of the pilot-valve being preferably at right angles to the axis of the main valve, so that the pilotvalve is movable transversely with respect to the main valve. The pilotvalve casing 2a is provided with an inner chamber 25, connected by a pipe 26 to the pressure ehamber14E, and at its outer end the pilotvalvc casing 2a is connected by a pipe 23 to'the exirausirchaniber 10.

The pilot-valve is provided with a central piston 29, which normally closes the connection between the pressure-chaniber or the cxhan =tchainber 27 with the passage leading into the ca ing 23. When the piston 29 of. the pilot-valve is moved to the right from, its norn al position, (illustrated in Fig. 1,) a passage between the pressure-chamber 25 and the itSlDgi, 23 will be opened, while when the piston 29 is moved to the left from its normal position a i sage between the exhaust-chamber 27 and 1e casing will be opened.

To operate the pilot-valve, 1 preferably provide a rod or connection comprising two sections adjns'tably thread ed together. s shown in 1, one of the sections or rod 30 cxtends out through a striding-box 3i. and is adjustably threaded into a second section or nut 32. The second section or not 32 is provided at its end with a recess for receiving a collar on the end of the stem of the pilotvalve, and said parts are pivotally connected Q, vase" e by a cap or collar 33, threaded onto the section or nut 32. The body portion of the section or nut 32 is provided with gear-teeth 3%, which mesh with a rack 35, extending down from the piston 22. The geared connection between the nut 32 and the rack 35 permits an endwise travel of the nut 32, and the raising' or lowering of the main valve-stem turns said not 32 through said geared connection. To hold the rack 35 in mesh with the gearteeth 34, I may, if desired, provide a guide piece or support 36 for the back side of the rack 35, as shown by dotted lines in Fig. 2. At its outer end the rod 30 is connected by a link 37 to a lever 38, pivoted in the bracket 39. At its lower end thelever 38 is connected to rope 40, which may be carried around the.

usual shi-iaves to the elevator-ear.

In the use of a hydraulic-elevator valve as thus constructed when the lever 38 is shifted by the controlling-rope 40 in the direction of the arrow P the pilot-valve will be shifted to admit pressure below the piston 22 to raise the main-valve stem and admit pressure to the,

elevator. hen the main valve is moved up to the desired position, the rack-and-gear connection with the threaded section or nut will have moved the pilot-valve back to its closed position. When the lever 38 is shifted by the controlling-rope 4:0 in the direction of the arrow E, the pilot-valve will be drawn in to vent the pressure below the piston 22, leaving an unbalanced pressure above the piston 22, which will move themain valve down to connect the elevator with the exhaust. The extent to which the main valve is shifted de-- pends upon the extent to which the pilot-valve is shifted, a large movement of the pilot-valve requiring acorrespondingly large movement of the main valve before the pilot-valve is brought to normal position.

One particular advantage of my construction is due to the fact that in all positions of the parts a constant ratio of travel is main:

tained between the main valve and the pilotvalve, whereas in constructions employing linkworh for connecting the main valve and pilot-valve there is no lixod ratio of travel be tween the main valve and the pilot-valve, the relative movement of said parts depending upon the ditlerent angular positions of the links or levers employed.

in the construction illustrated in the first sheet of drawings one section of the two-part connection which controls the pilot-valve is shiftedormovedlongitudinally,whiletheother section or nut is rotated. In some cases the nmvement of the pilot-valve may be caused exclusively by the threads between the parts. of the operating rod or connection, and I have illustrated such a construction in Fig. 3. As

shown in this figure, the rod 30 is journaled near its outer end in a bracket ll and is held from longitudinal movement by means of suitable collars. Sccnred on the outer end of the IIOl rod I provide a sheave or pulley 4:2 for the controlling-rope, which extends to the elevatorcar. struction is substantially the same as that before described, except that the initial shifting of the pilot-valve is caused by the screwthreaded connection.

In the actual construction of my hydraulicelevator valves I prefer to employ bronze or other non-corrosive metal for the operative parts, which are inclosed in the casing 23 and hence are submerged in water, although, if de sired, the operative parts may be located outside of the casing by providinga suitable stuning-box connection for carrying the rack 35.

I am aware that other changes may be made in practicing my invention by those who are skilled in the art without departing from the scope thereof as expressed in the claims. I do not wish, therefore, to be limited to the constructions I have herein shown and described; but

What I do claim, and desire to secure by Letters Patent of the United States, is-

1. An elevator-valve comprising a valvecasing, a main valve arranged therein, a pilotvalve arranged transversely to the main valve, a supplemental casing connected to the valvecasing, and connections between the main and pilot valves arranged in said supplemental casing.

2. In a hydraulic-elevator valve, the combination of a main valve, a pilot-valve, and a connection for operating the pilot-valve, comprising a part arranged to be shifted from an elevator-car, a second part threaded thereto, and a gear-and-rack connection between said second part and the main valve, said gear-andrack connection being arranged to permit an The operation of this form of conendwise travel of said second part while the rotation of said second part closes the pilotvalve when the main valve has been shifted to desired position.

3. In a hydraulic-elevator valve, the combination of a main valve, a pilot-valve movable transversely with respect to the main valve, a rod or connection for operating the pilot-valve, comprising a section arranged to be shifted from an elevator-car, a second section or nut threaded thereon, and a gear-andrack connection between the nut and main valve, said gear-and-rack connection being arranged to permit an endwise travel of the nut and to cause the rotation of the nut to close the pilot-valve when the main valve has been shifted to the desired position.

4. In a hydraulic-elevator valve, the combination of a main valve, a pilot-valve movable transversely with respect to the main valve, an operating connection for the pilotvalve, comprising sections threaded together, connections for sliding or shifting one of said sections longitudinally from an elevator-car, and a gear-and-rack connection between the other of sections and the main valve, said gear-and-rack connection being arranged to permit a longitudinal movement and to rotate one of said sections to cause the screw-threaded connection to close the pilot-valve when the main valve has been shifted to the desired position.

In testimony whereof I have hereunto set my hand in the presence of two subscribing vitnesses.

THURE LARSSON. Witnesses:

LOUIS W. SOUTHGATE, PHILIP SoU'rnGATn. 

